Self-fluxing silver alloy filler metal



United States Patent Ofi 2,777,767 Patented Jan. 15, 1957 ice 2,777,767 SELF-FLUXING SILVER ALLOY FILLER IVETAL Theodore I. Leston, New York, N. Y., assignor to Eutectic Welding Alloys Corporation, New York, N. Y., a corporation of New York No Drawing. Application September It 1953, Serial No. 379,473

3 Claims. (Cl. 75157.5)

This invention relates to a new brazing alloy, and more particularly to a brazing alloy of the type commonly described as German silver. More specifically, the present invention relates to a high silver, nickel brazing fiuxing agent.

It has long been common practice to formulate various type silver brazing alloys fluidity during the brazing operation, and which exhibit a function. Specifically, the alloy is of particular when used in conventional hydrogen furnace brazing operations.

According to the 9 Testing loy employs substantially greater silver than the known loys which are designed for speclfic heat treatable properties, as for example, as described in U. S. Letters Patent 2,101,087.

in particular, the known similar present, alloy distinguishes over such type filler metals in that it exhibits high exceptional capillary flow, good adherence, no fuming, a complete absence of dezincification and a selffluxing character.

Tests on the present alloy made in the usual manner according to the standards of the American Society for Materials, gave the following results:

Yield point (pounds per sq. inch) Tensile strength (pounds per sq.

inch) approx. 43,000 p. s. i. Elongation in 2 inches 35 percent Brinell hardness percent approx. 35,000 p. s. i.

From the foregoing, it will be obvious that the present alloy constitutes a type heretofore not realized. Adthe alloy exhibits improved corrosion resistance The following are the ranges of the which the self-fluxing alloy is preferably ing to the invention.

materials Within produced accord- Percent Copper 53- 56 Zinc 9- l1 Manganese 0.05- 0.5 ron 0.10- 0.5

Percent 54 55 the precise zinc content be very low.

A particularly efiective brazing operation was carried out in a hydrogen brazing furnace by the application of the following brazing alloy in rod form to ferrous materials. The alloy composition was as follows:

Percent Cu 55.03 Zn 10.15 Mn 0.09 Fe 0.10 Ni 7.76 Ag 26.75 The alloy may be formed by any of the conventional methods of smelting and mixing, but is preferably conducted in an electric furnace in a controlled, reducing atmosphere. The alloy may be molded or extruded in the form of rods, sheets, bars, etc. Alternatively, the alloy may be comminuted to provide a dust or granular mixture which can be brushed on the materials desired to be joined. Further, the alloy is not restricted in its utility to brazing operations, but can also be applied in the joining of steel and other ferrous materials, including cast iron, as well as non-ferrous materials, such as copper, brass, bronze, etc. The joining operation may be a brazing, fusion or arc welding one, and the alloy can be used as a filler metal or as an electrode core rod dependent upon the temperature at which the joining operation must be conducted.

As many apparently widely different embodiments of my invention may be made Without departing from the spirit and scope hereof, it is to be understood that my invention is not limited to the specific embodiments hereof except as defined in the appended claims.

4 What is claimed is: v 1. A self-fluxing silver brazing alloy composed of the following materials in the ranges indicated:

2. A self-fluxing silver brazing alloy composed of the following materials in the ranges indicated:

Percent Copper 54-55 Zinc 9.5-10.5 Manganese 0.05-0.1 Iron 0.10 Nickel 7.25-8.0 Silver 26-27 3. A self-fluxing silver brazing alloy having the following composition:

Percent Cu 55.03 Zn 10.15 Mn 0.09 Fe 0.10 Ni 7.76 Ag 26.75

2,279,284 Apr. 7, 1942 

1. A SELF-FLUXING SILVER BRAZING ALLOY COMPOSED OF THE FOLLOWING MATERIALS IN THE RANGE INIDCATED: 